Sanitising and disinfecting soap or cleaning compositions are of great benefit to individuals, since proper use generally may reduce the number of germs and pathogens the individual is exposed to. Thus, such compositions may for instance play an important role in reducing the occurrence and spread of infectious diseases.
Sanitising and disinfecting soap compositions comprising chlorine-based antimicrobial agents such as triclosan are known. Such compositions require a rather long contact time to provide efficacious antimicrobial action. In practice, users, in particular children, do not spend a long time on cleansing and as a result cleaning with such compositions does not provide adequate prevention from surface or topical infection or adequate protection against diseases. The user, in spite of cleaning his hands, is generally likely to end up with relatively inadequate bacterial removal from his skin. Therefore, he may cause contamination of further animate and/or inanimate surfaces and contribute to the spreading of pathogens and consequent diseases. Users in general and children in particular who wash contaminated hands before meals with slow-acting antimicrobial compositions for relatively short time are at risk of contracting diseases.
Similarly in the area of hard surface cleaning, e.g. cleaning of floors, table tops or utensils, the antimicrobial actives in the compositions are in contact with the substrate for less than a few minutes after which the surface is either wiped off or rinsed with water. These short time scales of cleaning action are ineffective in providing the desired benefit since most known antimicrobials commonly used in such products take many minutes to hours to provide the desired kill of microbes.
Therefore, there is a need of providing a composition that—upon application—provides relatively more efficacious antimicrobial action during a relatively short cleaning period, preferably about 30 seconds or less, more preferably 15 seconds or less.
A well-established class of antimicrobially active compounds are phenolic compounds [P A Goddard and K A McCue in “Disinfection, Sterilisation and Preservation”, ed. S S Block, 5th edition, Lippincott, Williams and Wilkins. Philadelphia, 2001 pp. 255-282.] However, not every phenolic compound is suitable as an antimicrobial agent. Moreover, many phenols—even if they are antimicrobially active—may exhibit undesirable side-effects, such as corrosiveness, malodour and irritating or sensitising effects when applied on the human or animal skin.
A particular problem of thymol is that its presence in a formulation is generally well-perceptible due to its olfactory properties. Although the latter may—at least to some extent—be appreciated in certain fragrance compositions, it is considered too intense by some users when applied at concentrations efficacious in rapid disinfection. Additionally, a lower concentration of odoriferous compounds including thymol or the availability of antimicrobial compounds that are less or not odoriferous allows greater flexibility to the manufacturer in providing alternative scents to his composition at lower doses. Hence there is a need to provide alternative antimicrobial compositions and methods that preferably require lower concentrations of thymol and/or have a more acceptable sensory profile.
WO 2010/046238 A1 describes an effective antimicrobial composition which provides rapid kill of pathogenic bacteria and which comprises 0.01 to 5% by weight of thymol, 0.01 to 5% by weight of terpineol and a carrier. WO 2010/046238 A1 also discloses a method of disinfecting a surface including the step of applying the above composition to the surface.
WO 11/117424 discloses viral inhibitor compositions for in vivo therapeutic use comprising a combination of (−)-carvone, geraniol and a further essential oil component.
WO 06/053458 is directed at providing bactericidal formulations containing perfume ingredients that have a rapid bactericidal effect against Gram-negative and preferably also against Gram-positive bacteria and a method for providing these formulations. The document discloses a formulation comprising (a) at least 0.2% (w/v) of one or more selected perfume ingredients, (b) 4% to 20% (w/v) of a hydrotrope and (c) 0.1% to 9% (w/v) of one or more selected surfactants. It also discloses that certain perfume ingredients have a rapid (30 s) bactericidal effect on gram-negative bacteria.
WO 06/120494 is directed at improving the performance of antibiotics, it discloses a pharmaceutical composition comprising at least one first substance selected from carveol, thymol, eugenol, borneol, carvacrol, their isomers, derivatives and mixtures thereof and at least one second substance which is an antibiotic, for instance amoxicilline.
WO 12/012385 is directed at providing compositions comprising one or more derivatives of essential oil compounds for use in personal care compositions (e.g. dentifrices) with beneficial therapeutic effects. It discloses a composition comprising one or more derivatives of parent essential oil compounds selected from aldehydes, ketones, alcohols, phenolics or acids, for use in personal care compositions, at a level of from 0.02% to 5.0% by weight to provide effective antimicrobial activity, preferably wherein the one or more derivatives are selected from acetals of the parent essential oil aldehydes or ketones; esters or ethers of the parent essential oil alcohols or phenolics; esters of the parent essential oil acids or mixtures thereof.
WO 01/67868 A2 is directed to acaricides. It also discloses an oil extracted from Chenopodium ambrosioides comprising inter alia carveol and thymol.
WO 2004/006679 A2 relates to compositions and methods for controlling plant-infesting pests with plant extracts, derived from Chenopodium species. It also discloses oil samples of plant parts above root, comprising inter alia carveol and thymol.
Masayoshi et al. [Biosci. Biotechnol. Biochem Vol 68(8), pp 1690-1697, (2004)] present a study of Citrus reiculata Bianco (ponkan) cold-pressed oil and its oxygenated fraction by GC and GCMS. It discloses that the aroma components of the oxygenated fraction of ponkan cold-pressed peel oil include inter alia perillyl alcohol and thymol.
FR 2 697 133 discloses biocidal and/or biostatic compositions, comprising mono-oxygenated sesquiterpenes of general formula C15HxO, wherein x is between 20 and 26 and aromatic compounds.
Despite the general availability of antimicrobial compounds and compositions, there remains a continuous need to find alternative antimicrobial compositions and active compounds that are suitable for use in such compositions. In particular, alternative compositions providing fast antimicrobial action remain highly desirable in view of current consumer habits. Such alternatives may reduce the dependency on current raw materials. Moreover, in the field of antimicrobials, the availability of alternatives may reduce the risk of development of microbial resistance or insensitivity to particular antimicrobial compounds.
In addition, there is a continued need to reduce the total amount of active ingredients required in such an antimicrobial composition. This need may for instance be driven by the desire for cost-efficiency, because such compositions are particularly relevant to developing countries. Moreover, reducing the amounts may also be beneficial for environmental reasons.
In view of the above-observed problems and drawbacks of the prior art, it is an object of the present invention to provide alternative antimicrobial compositions.
It is a particular object of the invention to provide such compositions, requiring a lower dose of antimicrobial compounds.
Similarly, it is an object of the present invention to provide an antimicrobial composition in which the olfactory contribution of the antimicrobially active compounds is reduced or in which the active compound contributes to providing a consumer-acceptable or even consumer-appreciated scent.
It is another particular object of the invention to provide an antimicrobial composition that contributes to reducing the required contact time in a method for disinfection of a surface.
In particular, it is an object of the invention to provide an antimicrobial composition which gives improved disinfection during cleansing of surfaces of the human body, such as the skin and the oral cavity.
It is yet another object of the present invention to provide an alternative method for sanitising and/or disinfecting, in particular of surfaces.
It is a further object of the invention to provide a method for disinfection with a reduced disinfection time. More specifically, it is an object of the invention to provide a method, wherein the disinfection time of the method is less than 300 seconds, preferably less than 120 seconds, more preferably less than 60 seconds, and even more preferably less than 15 seconds.
In particular, it is an object of the invention to provide a method for disinfection that gives improved disinfection during cleansing of surfaces, in particular hard surfaces, or surfaces of the human body, such as the skin and the oral cavity.